1. Field of the Invention
The present invention relates to a message service of a mobile communication, and more particularly, to a cell broadcasting service system and method.
2. Description of the Background Art
An SMS, an abbreviate for short message services, refers to a service for transmitting a data with a comparatively short length (usually from 80 byte to 160 byte) in a mobile communication network.
The SMS has been set up as the mobile communication network is developed to a digital method and a digital data is transmitted among inside the mobile communication network, a base station and a terminal. For the SMS, a terminal of a subscriber should have software supporting the SMS.
According to a transmission method, the SMS includes a point-to-point (p-t-p) type and a point-to-multipoint (broadcasting) type, based on which many SMS-related supplementary services are being developed.
As noted from what we call the two types, the point-to-point type is an SMS center to terminal type. More specifically, it signifies that a final destination is one terminal.
Meanwhile, in case of the broadcasting type, a final destination is every terminal, not a specific one terminal, if it can receive a message.
Especially, a minimum unit of the broadcasting in the CDMA network is a base station (cell), so that it is called ‘cell broadcasting’.
Another difference between the two types lies in a reliability in a data transmission. The point-to-point type can make a reliable data transmission. That is, a message center takes the responsibility of completely performing the transmission. However, in case of the cell broadcasting, if a user's terminal is in an OFF state or the line is busy, the user would fail to receive a corresponding message.
FIG. 1 is a drawing illustrating the construction of a general mobile communication system.
As shown in FIG. 1, the short message service system includes: a plurality of mobile stations (MSs) 50 for transmitting and receiving a short message; a base station 300; a mobile station center 400; a short message service center 500 for receiving the short message of the MS 50 and p-t-p transmitting it to a destination MS through the MSC 400; and a cell broadcast (CB) center 600 for broadcasting supplementary service information (weather information, traffic information and stock information, etc.) provided from each cell broadcast entity (CBE) 700 to an area where a service subscriber is located.
The CBE 700 is a sort of a server providing supplementary service information.
FIG. 2 is block diagram of a mobile communication terminal in accordance with a conventional art.
As shown in FIG. 2, the MS 50 includes: a key input unit 110 for generating a message data according to a key value inputted through a key pad; a controller 120 for converting the generated data according to a short message transmission protocol and generating a data burst message; and a radio module 150 for processing the generated data burst message so as to be wirelessly transmitted and transmitting it to the base station 300.
A short message transmitting process will now be described with reference to FIGS. 1 and 2.
When the user of the MS 50 depresses the key pad, the key input unit 100 generates a message data according to an inputted key value.
When the message data is generated, the controller 120 generates a transport layer message.
As the transport layer message is generated, the controller 120 generates a data burst message according to a GSM 04.1 and carries the transport layer message in the information field of the data burst message.
The radio module 150 processes the data burst message so as to be wirelessly transmitted and transmits it to the base station 300.
After being transmitted to the base station 300, the data burst message is transmitted to the SMS center 500 through the MSC 400.
Upon receiving the data burst message from the MSC 400, the SMS center 500 stores the received message in a memory and checks a destination address field of the data burst message. And then, the SMS center 500 checks whether a destination MS is in a receiving available state and transmits the data burst message to a corresponding MS.
FIG. 3 is an SMS protocol stack.
The SMS protocol stack is defined by a global system for mobile communications (referred to as ‘GSM’, hereinafter) standard (GSM 03.4), and as shown in FIG. 3, the SMS protocol stack should be implemented in each of the MS 50, the MSC 400 and the SMS center 500. Basically, the SMS protocol stack is a principle protocol between the MS 50 and the SMS center 500.
Functions for the SMS are implemented in the MS 50 and the SMS center 500, and the MSC 400 handles a relay function therebetween. By means of the relay function, an SMS message is transmitted to a base station that currently handles a service even in a hand-off situation or the like.
Each layer of the SMS protocol stack will now be described with respect to the operation of the MS 50.
First, the user inputs a message desired to be transmitted. Then, in an application layer, the inputted message is put together with various parameter values according to the type of message and transmitted to a transport layer.
In the transport layer, information on ‘to where the inputted message is to be transmitted’ or ‘whether a response is necessary’ is added to the message of the application layer to thereby generate a transport layer message.
The transport layer message is transmitted to a relay layer and carried on the data burst message of the GSM standard (GSM 04.1) in the relay layer.
The data burst message is transmitted to the base station according to a call processing routine defined in the GSM standard (GSM 04.1).
One of messages defined in the GSM 04.1, the data burst message is generated in the relay layer and a sort of container transmitting the SMS message (or a CB message). That is, it signifies an SMS message (or a CB message) created according to the GSM 03.4 (SMS standard) is carried on the data burst message defined by the GMS standard (GSM 04.1) and transmitted.
As shown in FIG. 1, the conventional cell broadcasting service system includes: a plurality of mobile stations (MSs) 50 for transmitting and receiving a short message; a base station 300; a mobile station center (MSC) 300; and a cell broadcast (CB) center 600 for broadcasting supplementary service information (weather information, traffic information, stock information, and the like) provided through the MSC 400 by each cell broadcast entity (CBE) 700 to an area where a service subscriber is located.
The CBE 700 is a sort of a server providing supplementary service information.
In order to do information providing business for subscribers, each supplementary service provider is allocated a cell broadcast identifier (CB ID) by a mobile communication provider, and a CB ID of a corresponding supplementary service provider is also stored in the service subscriber's terminal.
A general cell broadcasting service (CBS) process will now be described.
The CBE 700 generates a CB message in which supplementary information (i.e., weather information, etc), a CB ID value, broadcast range value, and the like, are stored.
And then, when the CBE 700 carries the generated CB message on the data burst message and transmits it to the CB center 600, the CB center 600 transmits the data burst message to a base station where the weather information service subscriber is located through the MSC 400.
Then, the base station broadcasts the data burst message to a plurality of unspecified MSs within the service area.
Each MS 50 determines whether to receive the message by referring to the CB ID of the broadcast message. That is, the MS 50 compares the CB ID of the broadcast message with its own CB ID, and if the two CB IDs are the same to each other, the MS receives the message.
In case of an MS that has not been subscribed for the weather information, it discards the broadcast message. If, however, an MS that has been subscribed for the weather information service, it receives the message.
As mentioned above, the SMS is a bidirectional transfer system while the CBS is a unidirectional transfer (from a provider to a subscriber) system.
Thus, the conventional cell broadcasting service (CBS) is of a passive transmission form that the subscriber is provided with information by the supplementary service provider, and since it is mostly provided for pay, it is less favored by subscribers. Also, at the side of the mobile communication providers, they are to be satisfied by a low business productivity.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.